Niners activate receiver Manningham, cut cornerback Asomugha

Wide receiver Mario Manningham is back for the 49ers, and could make an immediate impact.

That’s the hope anyway. Coach Jim Harbaugh’s 49ers are still looking for a reliable No. 2 receiver to complement Anquan Boldin — and San Francisco has the league’s lowest-ranked passing offense.

Manningham was activated Monday from the physically unable to perform list to the 53-man roster and will be available for Sunday’s home game against the Carolina Panthers.

The 49ers, 6-2 and riding a five-game winning streak following their bye week, also waived cornerback Nnamdi Asomugha and activated cornerback Eric Wright from the reserve/non-football injury list.

Manningham made 42 receptions for 449 yards and one touchdown in 12 games and 10 starts last season before injuring his left knee in a loss at Seattle Dec. 23. He underwent reconstructive surgery to repair torn anterior cruciate and posterior cruciate ligaments.

He has been practicing for two weeks, regularly with the first-team offense, and the Niners had until Tuesday to decide whether to add him to the 53-man roster from the PUP list.

Harbaugh said last week he hadn’t yet allowed himself to think about what the offense might look like with Manningham and top 2012 wideout Michael Crabtree — due back sometime this month from right Achilles tendon surgery — returning to the field.

The 32-year-old Asomugha began the season as San Francisco’s No. 3 cornerback and started in a Week 1 win against Green Bay, then played the next two games but hasn’t seen the field since Sept. 22 and had only two tackles. He also dealt with a knee injury, but was inactive the past three games even once healthy again.

Wright, who played at Riordan High School, signed a one-year contract in early August and was placed on the non-football injury/illness list while he handled a personal matter, the 49ers said.